{"id":"CVE-2021-20022","published":"2021-04-09T18:15:13Z","modified":"2026-10-01T21:17:15Z","title":"SonicWall Email Security Unrestricted Upload of File Vulnerability","vendor":"SonicWall","product":"SonicWall Email Security","tier":"core","eol":null,"description":{"text":"SonicWall Email Security version 10.0.9.x contains a vulnerability that allows a post-authenticated attacker to upload an arbitrary file to the remote host.","provenance":"source","from":"NVD"},"summary":{"text":"The flaw is an unrestricted file upload vulnerability in the SonicWall Email Security product, affecting version 10.0.9.x. An attacker who can reach the appliance over the network and holds valid credentials (post-authentication) can upload an arbitrary file to the remote host, with no user interaction required.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-23T07:06:26Z"},"cvss":{"score":7.2,"severity":"HIGH","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H","provenance":"source","from":"NVD"},"epss":{"score":0.16639,"percentile":0.97012,"date":"2026-10-29","provenance":"source"},"kev":{"dateAdded":"2021-11-03","dueDate":"2021-11-17","ransomware":true,"requiredAction":"Apply updates per vendor instructions.","notes":"https://nvd.nist.gov/vuln/detail/CVE-2021-20022","provenance":"source"},"vulncheckKev":{"dateAdded":"2021-04-20","exploitedFirstSeen":"2021-04-20","ransomware":true,"evidence":[{"url":"https://cloud.google.com/blog/topics/threat-intelligence/zero-day-exploits-in-sonicwall-email-security-lead-to-compromise/","date":"2021-04-20"},{"url":"https://www.fireeye.com/blog/threat-research/2021/04/zero-day-exploits-in-sonicwall-email-security-lead-to-compromise.html","date":"2021-04-20"},{"url":"https://www.ic3.gov/Media/News/2021/211029.pdf","date":"2021-10-28"},{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2021-11-03"},{"url":"https://cybersecurityworks.com/howdymanage/uploads/file/Spotlight%20Report%20-%20Index%20Update%20Q2%20-%20Q3%20-%20Final%20Version_compressed.pdf","date":"2022-05-18"},{"url":"https://www.ivanti.com/resources/v/doc/pr-survey-report/ransomware-quarterly-indexreport_q2-q3","date":"2022-10-21"},{"url":"https://www.mandiant.com/resources/blog/chinese-espionage-tactics","date":"2023-07-18"}],"evidenceTotal":7,"provenance":"source"},"exploited":true,"otx":{"pulseCount":50,"pulses":[{"name":"Actively_Exploited_Kev | Oct 29, 2026","url":"https://otx.alienvault.com/pulse/6ae20c1db17e7057ae7d9ad1","created":"2026-10-28"},{"name":"Actively_Exploited_Kev | Oct 28, 2026","url":"https://otx.alienvault.com/pulse/6ae0ba7e0e2a97ff7b218819","created":"2026-10-27"},{"name":"Actively_Exploited_Kev | Oct 27, 2026","url":"https://otx.alienvault.com/pulse/6adf68b85c3e852f3c111d18","created":"2026-10-26"},{"name":"Actively_Exploited_Kev | Oct 24, 2026","url":"https://otx.alienvault.com/pulse/6adb740e397c3ad4799aa4cd","created":"2026-10-23"},{"name":"Actively_Exploited_Kev | Oct 23, 2026","url":"https://otx.alienvault.com/pulse/6ada236fcfba2dfa730ea482","created":"2026-10-22"},{"name":"Actively_Exploited_Kev | Oct 22, 2026","url":"https://otx.alienvault.com/pulse/6ad8d33a077cbb5cab524d80","created":"2026-10-21"},{"name":"Actively_Exploited_Kev | Oct 21, 2026","url":"https://otx.alienvault.com/pulse/6ad78130c4d1ac2be83a8b6d","created":"2026-10-20"},{"name":"Actively_Exploited_Kev | Oct 20, 2026","url":"https://otx.alienvault.com/pulse/6ad62f63c24a405a3423cc13","created":"2026-10-19"},{"name":"Actively_Exploited_Kev | Oct 19, 2026","url":"https://otx.alienvault.com/pulse/6ad4dda174e5797d0bd238b7","created":"2026-10-18"},{"name":"Actively_Exploited_Kev | Oct 18, 2026","url":"https://otx.alienvault.com/pulse/6ad38c22e1848f8189d1c121","created":"2026-10-17"}],"provenance":"machine"},"cwes":[{"id":"CWE-434","name":"Unrestricted Upload of File with Dangerous Type"}],"references":[{"url":"https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0008","tags":["Vendor Advisory"]},{"url":"https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0008","tags":["Vendor Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-20022","tags":["US Government Resource"]}],"techniques":[{"id":"T1078","name":"Valid Accounts","tactics":["initial-access","persistence","privilege-escalation","stealth"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: Requires authenticated account access to exploit","mappingType":"exploitation_technique","evidence":[{"from":"description","quote":"allows a post-authenticated attacker to upload","start":72,"end":118}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"},{"id":"T1105","name":"Ingress Tool Transfer","tactics":["command-and-control"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: Arbitrary file upload delivers attacker tooling to host","mappingType":"primary_impact","evidence":[{"from":"description","quote":"allows a post-authenticated attacker to upload an arbitrary file to the remote host","start":72,"end":155}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"}],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2021-7485","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2021-7485","exploited":true,"exploitedSince":"2021-11-03","provenance":"source"},"exploits":[],"exploitSources":null,"exploitRefs":[],"flow":[{"stage":"exploitation","techniques":["T1078"],"provenance":"ai"},{"stage":"primary","techniques":["T1105"],"provenance":"ai"}],"timeline":[{"date":"2021-04-09","kind":"published","label":"Published (NVD)","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-20022","provenance":"source"},{"date":"2021-04-20","kind":"exploited-reported","label":"Exploitation first reported (VulnCheck KEV evidence)","url":"https://cloud.google.com/blog/topics/threat-intelligence/zero-day-exploits-in-sonicwall-email-security-lead-to-compromise/","provenance":"source"},{"date":"2021-11-03","kind":"kev","label":"Added to CISA KEV (known ransomware use)","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","provenance":"source"},{"date":"2021-11-03","kind":"euvd-exploited","label":"ENISA EUVD: exploited","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2021-7485","provenance":"source"}],"speed":{"daysToPublicExploit":null,"firstExploitFrom":null,"daysToKev":208},"priority":{"score":72.4,"factors":[{"name":"In a KEV catalog","points":35.0,"detail":"listed in CISA KEV and VulnCheck KEV"},{"name":"Recent KEV listing","points":0.0,"detail":"added 2018 days ago"},{"name":"Known ransomware use","points":10.0,"detail":"CISA KEV and VulnCheck KEV: Known"},{"name":"EPSS percentile","points":19.4,"detail":"percentile 0.9701"},{"name":"Named in threat reports","points":0.0,"detail":"0 reports"},{"name":"Public exploit code","points":0.0,"detail":"none found"},{"name":"Mentioned in OTX pulses","points":3.0,"detail":"50 pulses"},{"name":"CVSS severity","points":5.04,"detail":"base score 7.2"},{"name":"End-of-life product","points":0.0,"detail":"supported or unknown"}]}}